[Openicc] Google Summer of Code 2009: Oyranos CUPS backend

[Kai-Uwe Behrmann]

The "colourKeyWords" marker in PPD would be a realtively cheap way for 
matching a print configuration to a ICC profile.

Where would you like to see the rendering intent information apparing?
PPD?

kind regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org


Am 17.05.10, 08:48 -0400 schrieb Leonard Rosenthol:
> One thing we are working on at Adobe, that fits into this work, is a
> standard way to have printer manufacturers provide an actual ICC profile for
> their device that can be used as a real world "Output Intent".   Without
> such a profile, and with the increase usage around host-based CM, we are
> finding too many color shifting issues on various devices that expect colors
> to be "left alone".  In addition, we believe that information about
> rendering intent preference are also useful.
>
> So before you go hacking around the PPD format, you probably want to involve
> the various printer manufacturers and folks such as us, who are producing
> the PPDs that are distributed with the various OS platforms and devices, and
> whose applications also need to work with them.
>
> Leonard Rosenthol
> Adobe Systems
>
>
> On Sun, May 16, 2010 at 6:03 AM, Kai-Uwe Behrmann <ku.b at gmx.de> wrote:
>
>> Hello,
>>
>> the CUPS backend needs to tell Oyranos, which PPD colour related entries a
>> PPD has. These entries are used to select a meaningful user configured ICC
>> profile.
>>
>> Could you imagine a PPD entry, which solely lists all colour related
>> entries? Something like:
>> *colourKeyWords:
>> "ColorModel;StpColorPrecision;MediaType;StpQuality;Resolution;StpInkSet;StpInkType;StpBrightness;StpFineBrightness;StpContrast;StpFineContrast;StpSaturation;StpFineSaturationStpImageType"
>> Note this example is incomplete.
>>
>> A disadvantage might by that it has to be included into every PPD. For a
>> driver with a large number of supperted printers and hence many PPDs like
>> the Gutenprint one, it would mean to repeat that stuff. The advantage is a
>> included PPD entry would be very simple to parse along the CUPS delivered
>> PPD.
>>
>> Would this path be acceptable for foomatic, Gutenprint and hplib and other
>> vendors?
>>
>>
>>
>> kind regards
>> Kai-Uwe Behrmann
>> --
>> developing for colour management www.behrmann.name + www.oyranos.org
>>
>>
>> Am 19.08.09, 11:59 +0200 schrieb Kai-Uwe Behrmann:
>>
>>  Am 19.08.09, 11:16 +0200 schrieb Till Kamppeter:
>>>
>>>> Kai-Uwe Behrmann wrote:
>>>>
>>>>> What I do not know is, how to distinct the colour related PPD options
>>>>> from
>>>>> the non relevant to make selection dependent on say "gamma" but not on
>>>>> "paper size". Would you know a way how to select ppd_attr_t attributes
>>>>> according to their influence on colour?
>>>>>
>>>>
>>>> Principally one cannot read from a PPD option whether it influences color
>>>> or
>>>> not.
>>>>
>>>
>>> This will it make harder to get PPD to ICC profile mapping outside of the
>>> CUPS cupsICCProfile scheme. The need of root access to do proper colour
>>> management is yet clearly a limit.
>>>
>>> On the other side Oyranos needs to know if a PPD option or attribute is
>>> relevant for colour or not to do CM configuration outside of the
>>> cupsICCProfile scheme.
>>>
>>> E.g. a user printing to remote printer or on a system without root rights
>>> she can not locally assign a ICC profile to a given PPD in the Oyranos
>>> DB and keep flexibility without complicated tweaking. But exactly that was
>>> the goal we where aiming at in this years GSoC projects.
>>>
>>>  ICC profiles can be associated to choices of up to three options, by
>>>> default
>>>> to ColorModel, MediaType, and Resolution:
>>>>
>>>> *cupsICCProfile ColorModel.MediaType.Resolution/Description: "filename"
>>>> *cupsICCProfile RGB.GlossyPhoto.1200dpi/High-Quality Photo on Glossy
>>>> Photo
>>>> Paper: "Acme-PhotoStar-RGB-GlossyPhoto-1200.icc"
>>>>
>>>> Instead of MediaType and Resolution two other options can be used with
>>>> definitions like:
>>>>
>>>> *cupsICCQualifier2: Quality
>>>> *cupsICCQualifier3: ImageType
>>>>
>>>> See http://www.cups.org/documentation.php/doc-1.4/spec-ppd.html
>>>>
>>>
>>> Yes thats the next stage to support in order get the backend functional
>>> with cupsICCProfile.
>>>